In some conventional liquid ejection devices such as an inkjet printer, a liquid ejection device alternately executes a scanning operation of moving an ejecting head having a plurality of nozzles in a main scanning direction while causing the ejecting head to eject liquid droplets from the nozzles. These devices further provide a medium conveying operation of conveying a recording medium in a sub-scanning direction intersecting with the main scanning direction, while forming an image on the recording medium. In such liquid ejection devices, in a certain print mode, an image for the number of the nozzles arranged in the sub-scanning direction is formed in a path on the recording medium, and after the medium conveying operation, an adjacent image is formed in the next path. The scanning operation and the medium conveying operation are alternately repeated, and a predetermined image is formed on the recording medium.
In such a liquid ejection device, a shift may occur in the main scanning direction between the image formed in the previous path and the image formed in the next path. In some examples, such a shift between paths (inter-path shift) results from inclination of the nozzle surface of the ejecting head or the recording medium with respect to the sub-scanning direction, or a shift of the recording medium in the main scanning direction by the medium conveying operation. In the aforementioned liquid ejection devices, the nozzles of the ejecting head are divided into two nozzle groups in the sub-scanning direction, and liquid ejection timing is corrected to equalize an image shift between the two nozzle groups and an image shift between the paths.